Tripping mechanism for offset printing machines



. 0a. 14, 1958 c. A. HARLESS" ETAL 2,855,846

TRIPPING MECHANISM FOR OFFSET PRINTING MACHINES Filed A 16, 1954 5 Sheets-Sheet 1 Cannes 4 HnRLEss Baeraw C. fineness, Je.

INVENTORS.

ATTORIVEXS c. A. HARLESS ETAL 2,855,846

Oct. 14, 1958 TRIPPING MECHANISM FOR OFFSET PR INIING MACHINES Filed Aug. 16. 1954 3 Sheets-Sheet 2 Oct. 14, 1958 c. A. HARLESS El'AL 2,855,846

TRIPPING MECHANISM OFFSET PRINTING MACHINES Filed 8- 16, 1954 I 3'Sh eets-Sheet 5 CHARLES 4. Hquess Buermv v6. PawLase, J12.

, M INVENTORS,

4 T TOR/V6215- United States Patent Ofiice 2,855,846 Patented Oct. 14, 1958 TRIPPINGMECHANISMl FOR-:. OFFSET ERIN TIN G MACHINES" (Zh'arlesAtHarless, Riverside,-Conn-., and Burton C. Pol- Gotinc, NewtYrk,,N. ill, ,a-:corporation: of N ew: :York

Application August 16', 1954; Serial No. 4495927 Srfilaimsa (Climb-218) This invention-relates to trippingmechanismfor print ing machines, and more particularly for web; ofiset print ing machines.

It is an object of-th'einvention to providea' tripping;

mechanism of simplified construction.

A further object is to K providesuch a mechanism incorporating also an impression adjustment.

still furtherobjectis to provide improved arrangements-foralternatively tripping aprinting unit or-selected components thereofi With= theseobjects and'stillj' other objects, which will.

Fig. l is a'schematic,.lin'kagediagram'ofithe mechanism.

of the -invention Fig: 2js an enlarged 'detailview offthe trip 'sliaftmechar Fig; 5 is'a section on line 5- -5 of.fF ig 1;,showingthe,

motor drive? arrangement; and

Fig, 6 is adetail view online 6I-6 '0 ffFig.,,5.-showing an indexing; arrangement.v

Theprinting; unit. generally is of. the type shown.

Huck Patent 23 66,33 5, an djin ,which two, impressions are printedgsimultaneously on the ;two sides-,ofta web. W byrar pair'ofiblanket cylinders or,v ofiSet printing cylinders each,

serving as impression cylinder. for the other.. In the par:

ticular machine illustrated the web, travels; in. a; horizontal printing units,:, or; two halvesv of t the.

pathanck the two double. printing unit, are superposed, one directly; over the other,

not 'shown herein.

The upper half gofthe unitcomprises a, blanket cylinder.

10; a plate cylinder 11, ink motionformrollersr12, and:

ink drums 13 (generally called vibrators), for inking the form rollers. As will. belunderstood a' further train of inkd'rums androllersv andran inkr pump or fountain will form parts ofth e, inkmotion,supplyingink tothe drums 13'; These elements are known, andsince they. form no part of {the present invention, they-will not; be described herein. Further form rollers 14. forming partofa, Water motion also cooperate with the plate-cylinder ll, asusual.

The; lower half of:the unit is similar to the upper; half, and its construction and operation, will beunderstood from the following description of..the (upper, half.

The lower blanket cylinder 10' is carriedlin fixed-bearingss 1'6" While the upper blanket cylinder is.carried in bearings 1'6 mounted'in eccentric bushings 17, which are rotatable'in the frames, so that the. axial distance between cylinders 10 and 10' may be adjusted, for regulating the printing pressure and'accommodating webs of different thicknesses; by a small angular movement of bushings 17."

Front and backmaintframes, support similar bearingsjfor the various cylindersand, rollers,,a-lthough;

Turning: bushings 17 through a: larger: angle: separates. the cylinder: 10 fromcylinder 10" for. tripping: off" the: im pression;

The bearings oflplatezcylinder; 11 are-carriedin ecceni tricbushings 18, rotatable in theiframes, for moving this cylinder: inthe vertical direction,- as later" described Turning these bushings slightly, along with bushings-i17 causes plate cylinder 11 to followblanket cylinder 10=in its small adjusting movements, while turning bushings" 18" through a larger angleseparates cylinders 10 and 11}. tripping the plate cylinder away from the blanket cylin'der:

Further eccentric bushings 20'are'rotatively oarrie'd'Zbythe eccentrics 18 0i cylinder; 11, and carryrtriprings- 22 fontli'e ink motion; Poppet rod connections- 24'- to? the" form roller sockets'or movablesupports, provide-for-trip ping the ink' motiom. Turning the bushihgs' 20' causes. a". vertical b'odil'y movement of rings22which', through the: poppet rods 24" forces the-form rollers 12" away' from" cylinder 11, thus tripping otfthe ink'motion; In their movements toward" andaway from'cylinder IIthesefbrm rollers-12 swingaboutthevibrators 13; which rotateon'. fixedax-es, asdescribed in Harlessand P-olglaseapplicasv tion, Serial'No. 427,728,1filed May'S, 1954; for Roller Socket Mounting,- now Patent No. 2,818,805.

The mechanism for-producingtherequired' movement s; comprises trip shaft assemblies onboth front and". rear frames, togetherwith suitable'connecting arms'or links; thetripping being accomplished by a rotary shaftxnrove ment and the impression adjustmentbya bodily ortransa lati'onalmovement of the-shaft :assemblies.

For *clearness ofillustration', the essential elements and" their connections to" the-tripping eccentrics'are shown in: theform ofa linkagediagrampin'Fig, 1; andthe detailed. construction of the essential parts is shownlin the later figures.

InFig; 1 there is'indicatedatA an'arm pivotally, sup portediatB -uporra slidable' block members 33., Links 'or connecting,rods.,40; 43 and.45 respectively, connect; the eccentrics ,17 ,1 18andt20' to arm ,A at points 42', 44 and 46;, progressively further away from the pivot'B'; The link.-- age. is shown in. tripped'otf" position, ,andthe elements are..-

' tripped oniby turning arm A' counter-clockwise tog-the:

dottedline positionA', Inthelatter position armvAk andthelinks 40; 43and 45 are;all,aligned together, andf their points of attachment 40', 43""and'45', toleccentricss 17, 18 "and'2'0', will have movedi respectively. to 41!, 431

and, 45" and. .be in alignment, with, the dotted=linet A;

It will begunderstood, that theeccentricsl7, ,18,and,20, ,thc connecting-rods 40, 43and"45,th'e'arm Aandflthe slidable block'BIare duplicated :on theopposite sidetof the machine. from ,thatshown inJFig, 1, Groovesizflv (Rig l), arecut;

*inthesfiames to guide.the. slidable:blocktmembersrfor;

movement along the line vA.

With therparts ,inrtripped.,onf ppsition,,the,blocks 33 may be adjustedlalong'the dotted line A? to raisezorilowert theupper. blanketacylinder 10; with: relation. to .the lower, blanketzcylinder, 10, to regulate-thetimpressiorrpressure. or to provide for a change in the thickness of the paper; to bQrPI'll'ltCd without changing; the distance, between the axesof the cylinderslO. and 11, northe relationship;.of; thecform rollers 12 to' theicylinden 11.

By, reasonef; the progressively; longer crank arms-:fon the .links.40, 43sand '45, turning the arm Aifrom tripped: on (dotted line AC) to tripped-off; (solid lines) position;, moves theblanket cylinder 10, platelcylinder.11..and-form:, rollers 12, through. progressively greater distances, the-tree sult being to tI'lPJOfiQthB impressiomplate and inkqmotion separating these elements fromtheir cooperating elements the ink motion, plate andblanket, respectively. 'lh'ese shafts are indicated collectively as the pivot B inthe schematic showing of Fig. 1. Shaft 30 is rotatively supported in bearings carried by blocks 33 slidably mounted on the machine frame structure, shaft 31 is rotatively supported on shaft 30 by bushings 34 and shaft 32 is rotatively supported on shaft 31 by bushings 35. The required rotary movements are imparted to the shafts through crank arm 36 fixed to shaft 32, connecting rod 37 and an arm or a bell crank which is driven as later described.

Trip shaft 32 connects to the eccentric bushing 17 through a connecting rod 40, pivotally connected to these two elements at 40, 42. The crank arm, or distance from point 42 to the axis of shaft 32 is short, as shown. Similarly shaft 31 connects to eccentric bushingsls by a connecting rod 43, pivotally attached tothe bushing and to a crank arm or plate 44 which is fixed to the shaft 31, and shaft 30 connects to the eccentric bushing 20 bya connecting rod 45 and crank arm or plate 46 fixed to shaft 30. The crank arms 42, 44, 46 are progressively larger, as shown. (They are indicated collectively as the arm A of Fig. 1.)

Crank plate elements 42, 44 and 46 are rcleasably coupled together by adjustable screw and slot connections. The outer shaft element 42 carries a coupling pin 52 passing into a bore 53 in the middle or intermediate shaft element 44. Similarly, intermediate shaft element 44 carries a coupling pin 50 passing into a bore 51 in the inner shaft element. By this means the shafts 30, 31 and 32 are coupled together in desired angular relationship, or may be released for separate movement. Turning shaft 32 turns shafts 31 and 30, coupled to it, and through connecting links 40, 43, 45 turns the bushings 17, 18 and 20. The crank arms are so related to: the eccentricities of the bushings as to produce progr'e'ssively greater movements of the cylinder 10, cylinder 11 and form rollers 12 so that all elements are separated or tripped off.

The parts are so arranged that, in the tripped-on position, the connecting rods 40 and 43 and the common axis of shafts 30, 31 and 32 are aligned or coplanar, and the blocks 33 are guided in grooves 29 in the'frame, as shown, to move along this same line or, in this same plane. (This is the line A of the schematic Fig. 1.) The effect of a sliding adjustment of blocks 33 will therefore be to cause equal movement of the points of attachment of rods 40, 43 to their eccentrics. The parts are also so arranged that radii to these points of attachment make equal angles to the connecting rods (as shown, 90) and the radii are equal in length. The eccentricities of bushings being also equal (or proportional to the radii, more generally) a movement of blocks 33 moves cylinders 10, 11 as a unit without disturbing their relation to each other. The parts are further arranged so that, in the tripped-on condition, connecting rod 45 for the ink motion is also aligned with, or coplanar with shafting 30-32 and the rods 40, 43, the connections of rods 43 and 45 to their eccentric bushings being substantially superposed. The result is to vary the impression without affecting the inking of the plate cylinder or the transfer of ink from plate to blanket cylinder.

The bodily adjustment of shafting 3032 by shifting blocks 33 is accomplished by means of nuts or internally screw threaded members 60 (Figs. 2 and 3) receiving the threaded projectionsfil of the blocks 33, and rotatively carried in the frame structure, as shown. Members 60 are externally formed with worm wheel teeth 61 engaging worms 62 carried on a shaft 63 journaled in the frames and rotated by a crank 64.

The mechanism for operating the tripping mechanism by rocking bell crank 38 about the stud or stub shaft 39 on which. it iscarried, comprises a link 70 connecting theother arm of the bell crank to a motor driven crank 71 carried by shaft 72. A link 70' serves to 4 operate similar tripping mechanism for the plate and ink motion of the lower half of the unit. This shaft 72 is driven through bevel gearing 73 from a shaft 74, which is driven through clutch elements 75, 76 by an electric motor reducer unit 77.

An indexing wheel 78 carries a tooth or projection 79 for engaging either of a pair of micro-switch operat ing arms 80, spaced 180 apart. The indexing wheel therefore stops the motor whenever the shaft 74 reaches either of two positions corresponding to tripped-on and tripped-off positions of the mechanism.

A pair of adjustable stops 81 (Fig. 2) are provided for limiting movement of the trip shaft in the tripped-on and tripped-off position, and the links 40, 43 and 45 are provided with the usual turn buckle adjustments. In initially setting up the equipment, the micro-switches 80 are adjusted to obtain a desired rocking movement of the trip shafts 30-32, and the stops 81 are set in the extreme positions of movement. By adjusting the links 40, 43 and 45, desired corresponding positions of the plate cylinder, blanket cylinder and form rollers are thus provided for. The stops 81 may now be backed off slightly, but will serve to limit manual movement of the parts.

As shown in Figs. 2 and 4, a cover plate 90, indicated in phantom in Fig. 2 is provided. This member is rotatably carried by a disc 91 mounted on a stub shaft 92. The cover plate is shaped so as to accommodate the heads of coupling pins 50 and 52 when the latter are in the coupling position, of Fig. 4, but not to accommodate the heads of these pins when pulled out to uncouple either or both of the crank plates 42 and 44. As will be noted, notches 93 in the shanks of these pins cooperate with spring pressed ball detents to hold the pins in either coupling or uncoupling positions. Since the cover 90 cannot be swung down to the position of Fig. 2 if either pin 50 and 52 is pulled out the fact that this cover is in the downward position is assurance that the crank arms are coupled together. The position of the cover or guard 90'is used to insure that power operation of the tripping mechanism will not be attempted unless all the elements are properly coupled together. This result is achieved by forming disc 91 with a depression 95 which receives a roller 96 carried on the operating arm 97 of a micro-switch 98. Whenever the arm 97 is lifted, the power supply for the tripping motor 77 is interrupted, and an operating circuit is established when the disc 91 is in the position of Fig. 2. The tripping motor is preferably operated manually under normal conditions, but is arranged to trip oif the impression automatically if the feeding of the web is interrupted.

Sockets such as are shown at 208 in the Huck Patent 2,366,335 are provided to receive a suitable bar for turning the shafts 30, 31 and 32 manually, and by manipulating the coupling pins 50 and 52, any of the shafts may be operated separately when it is desired to make adjustments to the machine.

What is claimed is:

1. In a web offset printing machine, tripping mechanism comprising a trip shaft, crank means thereon comprising a crank arm, link and pivot connecting the same to the crank arm for tripping each of the impression, the plate and the ink motion, respectively, means mounting the trip shaft for aligning all the said links and the trip shaft axis in tripping-on position, the last said means comprising a block rotatably supporting the trip shaft, means for adjustably positioning the said block in the direction of alignment for varying the impression, and means for releasably coupling the said crank arms together for tripping the unit and for uncoupling the crank arms to trip the ink motion and plate separately.

2. Ina web offset printing machine, tripping mechanism ,comprising a plurality of concentric trip shafts, a crankmeans on .each shaft, links and pivots connecting them to the crank means for tripping the impression, the

plate and the ink motion, respectively, means mounting the trip shafts for aligning all the said links and the trip shaft axis in tripping-on position, the last said means comprising a block rotatably supporting the trip shafts, and means for adjustably positioning the said block in the direction of alignment for varying the impression, power means for rotating one of the trip shafts and releasable pin couplings connecting said shafts, whereby the plate, ink motion and impression may be tripped manually and separately as well as by power and together.

3. In a web offset printing machine, tripping mechanism comprising a trip shaft, crank means thereon, links and pivots connecting them to the crank means for tripping the impression, the plate and the ink motion, respectively, means mounting the trip shaft for aligning all the said links and the trip shaft axis in tripping-on position, the last said means comprising a block rotatably supporting the trip shaft and means for adjustably positioning the said block in the direction of alignment for varying the impression, and power means for rocking the trip shaft between predetermined trippingon and tripping-off positions.

4. In a web ofiset printing machine, tripping mecha nism comprisinga trip shaft, crank means thereon, links and pivots connecting them to the crank means for tripping the impression, the plate and the ink motion, respectively, means mounting the trip shaft for aligning all the said links and the trip shaft axis in tripping-on position, the last said means comprising a block rotatably supporting the trip shaft and means for adjustably positioning the said block in the direction of alignment for varying the impression, and electric power means for rocking the trip shaft between predetermined tripping-on and tripping-01f positions and indexing means for deenergizing the said electric power means in the said positions.

5. In an ofiset printing machine having a frame rotatably supporting first and second blanket cylinders between which a web is printed on both sides simultaneously, a plate cylinder co-acting with the first blanket cylinder and inking rollers co-acting with the plate cylinder, hearings in the frame to support the second blanket cylinder for rotation on a fixed axis, first eccentric bushings in the frame to support the first blanket cylinder for movement toward and away from the second blanket cylinder, second eccentric bushings in the frame to support the plate cylinder for movement toward and away from the first blanket cylinder, and third eccentric bushings associated with the second eccentric bushings to support the ink rollers for movement toward and away from the plate cylinder, and in combination, a pivoted arm device adapted to rotate the first, second and third eccentric bushings simultaneously for tripping the blanket and plate cylinders and the ink rollers, means operable to adjust the position of the pivot for the pivoted arm device to vary the distance between the axes of the blanket cylinders without changing the relative position of the plate cylinder and the first blanket cylinder, and means connecting the said pivoted arm device to the said eccentric bushings for effecting conjoint and equal movement of the said first blanket cylinder and the plate cylinder in response to adjustment of the position of the said pivot.

References Cited in the file of this patent UNITED STATES PATENTS l,8l6,796 Rossger July 28, 1931 1,969,311 Pearson et al. July 10, 1934 2,278,312 Holtz Mar. 31, 1942 2,425,327 Janke Aug. 12, 1947 2,653,539 Halley Sept. 29, 1953 

